Aly Ibrahim, Taher Eman E, El Nain Gehan, El Sayed Hoda, Mohammed Faten A, Hamad Rabab S, Bayoumy Elsayed M
Parasitology Laboratory, Theodor Bilharz Research Institute, Giza, Egypt.
Clinical Parasitology Department, Research Institute of Ophthalmology, Giza, Egypt.
Acta Trop. 2018 Jan;177:19-24. doi: 10.1016/j.actatropica.2017.09.024. Epub 2017 Sep 28.
Nanotechnology is a promising arena for generating new applications in Medicine. To successfully functionalised nanoparticles for a given biomedical application, a wide range of chemical, physical and biological factors have to be taken into account. Silica-coated nanoparticles, (SiO2NP) exhibit substantial diagnostic activity owing to their large surface to volume ratios and crystallographic surface structure. This work aimed to evaluate the advantage of bioconjugation of SiO2NP with PAb against Toxoplasma lyzate antigen (TLA) as an innovative diagnostic method for human toxoplasmosis. This cross-sectional study included 120 individuals, divided into Group I: 70 patients suspected for Toxoplasma gondii based on the presence of clinical manifestation. Group II: 30 patients harboring other parasites than T. gondii Group III: 20 apparently healthy individuals free from toxoplasmosis and other parasitic infections served as negative control. Detection of circulating Toxoplasma antigen was performed by Sandwich ELISA and Nano-sandwich ELISA on sera and pooled urine of human samples. Using Sandwich ELISA, 10 out of 70 suspected Toxoplasma-infected human serum samples showed false negative and 8 out of 30 of other parasites groups were false positive giving 85.7% sensitivity and 84.0% specificity, while the sensitivity and specificity were 78.6% and 70% respectively in urine samples. Using Nano-Sandwich ELISA, 7 out of 70 suspected Toxoplasma-infected human samples showed false negative results and the sensitivity of the assay was 90.0%, while 4 out of 30 of other parasites groups were false positive giving 92.0% specificity, while the sensitivity and specificity were 82.6% and 80% respectively in urine samples. In conclusion, our data demonstrated that loading SiO2 nanoparticles with pAb increased the sensitivity and specificity of Nano-sandwich ELISA for detection of T.gondii antigens in serum and urine samples, thus active (early) and light infections could be easily detected.
纳米技术是医学领域开发新应用的一个充满前景的领域。为了使纳米颗粒成功地用于特定的生物医学应用，必须考虑广泛的化学、物理和生物学因素。二氧化硅包覆的纳米颗粒（SiO₂NP）因其大的表面积与体积比和晶体表面结构而具有显著的诊断活性。这项工作旨在评估SiO₂NP与抗弓形虫裂解物抗原（TLA）的单克隆抗体进行生物共轭作为人类弓形虫病创新诊断方法的优势。这项横断面研究包括120名个体，分为：第一组：70名基于临床表现疑似感染弓形虫的患者；第二组：30名感染除弓形虫之外其他寄生虫的患者；第三组：20名无弓形虫病和其他寄生虫感染的明显健康个体作为阴性对照。通过夹心ELISA和纳米夹心ELISA对人类样本的血清和混合尿液进行循环弓形虫抗原检测。使用夹心ELISA，70份疑似弓形虫感染的人类血清样本中有10份呈假阴性，30份其他寄生虫组样本中有8份呈假阳性，敏感性为85.7%，特异性为84.0%，而尿液样本中的敏感性和特异性分别为78.6%和70%。使用纳米夹心ELISA，70份疑似弓形虫感染的人类样本中有7份呈假阴性结果，该检测方法的敏感性为90.0%，30份其他寄生虫组样本中有4份呈假阳性，特异性为92.0%，而尿液样本中的敏感性和特异性分别为82.6%和80%。总之，我们的数据表明，用单克隆抗体负载SiO₂纳米颗粒可提高纳米夹心ELISA检测血清和尿液样本中弓形虫抗原的敏感性和特异性，从而能够轻松检测出活动性（早期）和轻度感染。
